Itzik Ben-Gan

Itzik Ben-Gan is an independent T-SQL Trainer. A Microsoft Data Platform MVP (Most Valuable Professional) since 1999, Itzik has delivered numerous training events around the world focused on T-SQL Querying, Query Tuning and Programming. Itzik is the author of several books including T-SQL Fundamentals, T-SQL Querying and T-SQL Window Functions. He has written articles for sqlperformance.com, ITPro Today and SQL Server Magazine. Itzik’s speaking activities include PASS Data Community Summit, SQLBits, and various events and user groups around the world. Itzik developed and is regularly delivering his Advanced T-SQL Querying, Programming and Tuning and T-SQL Fundamentals courses.

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Itzik Ben-Gan 02 January 2024

Two-Dimensional Interval Packing Challenge

Packing intervals is a classic SQL task that involves packing groups of intersecting intervals to their respective continuous intervals. In mathematics, an interval is the subset of all values of a given type, e.g., integer numbers, between some low value and some high value. In databases, intervals can manifest as date and time intervals representing … Read more

Itzik Ben-Gan 28 September 2023

T-SQL Fundamentals: Controlling Duplicates

When people start learning a new field, for example T-SQL, it’s tempting to spend very little time trying to understand the fundamentals of the field so that you can quickly get to the advanced parts. You might think that you already understand what certain ideas, concepts and terms mean, so you don’t necessarily see the … Read more

Itzik Ben-Gan 29 May 2023

T-SQL Gap-Filling Challenge

T-SQL Programming

A student of mine sent me a T-SQL challenge involving gap-filling of missing dates and balances. I found the challenge interesting and common enough and figured that my readers would probably find it interesting to work on as well. I’ll present the challenge and three possible solutions, as well as the results of a performance … Read more

T-SQL Programming